Has anybody every taken one in the wild? I have seen pictures of these birds on certain lakes (usually in the park areas) around DFW? They would make a great mount.

I doubt it, to my knowledge we dont have a wild population here

Not so, rickym. We had Mandarins on our property in Ivanhoe from at least 2009 through 2015. They usually arrived with Woodies in the spring and left shortly after the molt.

I've seen them on NE Texas lakes. If I remember correctly, they're not protected.

Someone posted a picture of one taken in Louisiana a year or two ago.

If you shoot a Mandarin in N. America you are shooting someones escaped pet. Nothing wrong with that - they are beautiful birds!

Correction. If you shoot one in the US you are shooting the offspring of someone's pet.
Private reserves have been releasing them for years for "executive" hunters. Enough have gotten away that they have started to establish themselves.
I hunted at one with a gun manufacturer in Minnesota a few years ago. They turned loose about 100 that day. Most were shot but several flew away. The manager said they lose several just about every time they have a shoot.

There are large feral flocks isolated in parts of the US... mainly in La, SC, and Ca

The Mandarins that stayed with us escaped from a hatchery near Bonham TX when a storm blew over a portion of their fencing. The Mandarins seemed to have joined up with their Wood Duck cousins. However, the Mandarins are feisty little buggars and would run off Woodies and even Mallards at the feeders. This pic was taken in September of 2010 at our property in Ivanhoe.